On FreeBSD, the customary places for documentation of the ported software
is under /usr/local/share/doc/<port name>.

--- tkp4.tcl	Thu Sep 13 18:48:49 2001
+++ tkp4.tcl	Fri May 17 15:48:48 2002
@@ -1893 +1893 @@
-            p4_viewDialog show "TkP4 - Changes" [p4_fileGetText [file join $p4(libdir) CHANGES]]
+            p4_viewDialog show "TkP4 - Changes" [p4_fileGetText [file join $p4(libdir) .. doc tkp4 CHANGES]]
@@ -2032 +2032 @@
-            p4_viewDialog show "TkP4 - P4Win Differences" [p4_fileGetText [file join $p4(libdir) P4WINdifferences]]
+            p4_viewDialog show "TkP4 - P4Win Differences" [p4_fileGetText [file join $p4(libdir) .. doc tkp4 P4WINdifferences]]
@@ -2038 +2038 @@
-            p4_viewDialog show "TkP4 - Using" [p4_fileGetText [file join $p4(libdir) UsingTkP4]]
+            p4_viewDialog show "TkP4 - Using" [p4_fileGetText [file join $p4(libdir) .. doc tkp4 UsingTkP4]]